Ah, you've stumbled into the anti-mask paradox. The anti masker simultaneously believes that masks block so much airflow that they will give you brain damage AND they do nothing to limit the airflow that could contain the virus.
I'll give you a great analogy. You may have seen the mosquito through a chain link fence reference, I have another one. We have a drainage ditch in the back yard, the neighbors rain water is directed through it. We had wood privacy fence there, with a big opening at the bottom. We put a a large metal grid there to keep the dogs from getting out. I'm talking like 4" squares. Yes, water normally goes through it. But it when it rains really hard (think breathing hard or rapidly) the water was restricted and it pushed so hard it knocked over the whole fence. It snapped 4x4 posts. This is what happens with kids or anyone exerting themselves. Athletes fall down, people get headaches,
@cb1111 gets brain damaged, etc. They get CO2 retention or trapping, this has been proven. Some clown performing surgery in 65 degree climate controlled room is not going to exert themselves like this. Now consider all the debris that is much larger (like a virus) than water (like air) but still goes right through that fence. Some gets trapped, but not the bulk by any means.